Retractable awnings are commonly used on recreational vehicles or buildings to provide overhead protection against the sun, rain, etc. Such awnings are typically permanently mounted on the vehicle or building to extend outwardly from one side thereof, such as the side on which a door is located. The awnings are collapsible for storage. In typical basic construction, this type of awning commonly includes a fabric canopy having an inward edge portion attached along the upper portion of the sidewall of a building or vehicle. The outer edge portion of the canopy is secured to a support tube, usually hollow and sometimes with a wind-up mechanism to roll the canopy around the support tube in a manner somewhat similar to the operation of a window shade. Usually, the support tube is constructed with one or more longitudinal grooves for receiving a bead formed at the outer edge of the canopy. The support tube is supported by telescoping legs which extend either downwardly to the ground or backwardly to low anchor points on the vehicle. In addition, telescoping arms or struts extend outwardly from the upper portion of the vehicle or building wall to intersect the ends of the support tube.
When the awning is not in use, the support struts are retracted and disconnected and the support legs are retracted to place the support tube alongside the vehicle or building wall with the canopy rolled up thereon. For extension of the awning, the legs, attached to the ends of the support tube, are extended and the support struts are telescoped outwardly to force the support tube away from the vehicle or building thereby unrolling the canopy from the tube. Examples of such vehicle or building awnings are disclosed by U.S. Pat. Nos.: 3,789,903; 3,918,510; 4,020,888; 4,077,419; 4,164,972; 4,171,013; and, 4,188,964.
One difficulty with known awnings, such as those disclosed in the foregoing patents, is that the intermediate portion of the support tube, especially in longer awnings, tends to sag downwardly under its own weight. Also the intermediate portion of support tubes, again especially on longer awnings, tends to bow inwardly toward the vehicle or building thereby failing to maintain the canopy in taut condition, causing it to sag or flap excessively in the wind. Another common problem with awnings is that the wind tends to lift the canopy, together with the support tube, upwardly. It can be appreciated that the reaction of the wind against the large surface area of the canopy can generate a substantial upward force acting on the awning.
To overcome the difficulties of known awnings, the present invention provides various supporting members for supporting an awning, including auxiliary support legs which can be used to support the intermediate, or even the ends of the support tube. The present invention also provides supporting members in the form of auxiliary rafters or compression members that push outwardly against the intermediate portions of the support tube to assist in maintaining the canopy in taut condition. In addition, tie-down straps are provided to anchor intermediate portions of the support tube to the ground.
In known awnings attachment of supporting members to awning support tubes, such as in the types shown in the '621, '419, and '510 patents, require either a permanent attachment point be provided on the support tube or access to the ends of the support tube to insert fittings into the grooves of the support tube. Thus, either modification of existing support tubes for providing permanent attachment points is required to add additional or optional supporting members. Alternatively, access to the ends of the support tubes is required so that such optional members could be engaged with longitudinal grooves extending along the length of the support tubes. However, the support legs attached to the ends of the tube and perhaps portions of the wind-up mechanism must be disassembled to gain this access. The present invention overcomes this difficulty of known awnings by providing an attachment or clamping assembly whereby optional supporting members, such as legs, rafters or compression members, and tie-down straps can be conveniently attached to the support tube at any desired location along the tube without requiring modifications to the tube or access to the ends of the tube.